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Discussion Starter · #1 ·
Well, we took care of the fuel pressure problem, but her shifting between 45 & 55 mph is all over the place. She shifts down from overdrive to 4th then to third and rpm's go flying. When we are supposed to be in overdrive she likes 3rd and keeps going back to it. She down shifts going up hill and banking left on highway exits. She's fine on the right banks. If I can get her over 55 warm and 60 cold she's ok in overdrive. I don't understand what's wrong. Please help me fix her.....
 

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Have you checked your grounds and battery connections? These trucks can be sensitive to voltage problems
 

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Hows the tranny fluid? Red and doesnt smell burnt?
 

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Discussion Starter · #4 ·
The battery guage is giving off a slight overcharge. I'll send a picture a bit later. Last time I checked, before the fuel issue. The transmission fluid look kind of orangish but didn't smell burnt. I will check again after work.
 

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Sorry to hear it wasnt a cheap fix bud.

2000 2wd, 5 speed, 150hp injectors, fass, exhaust brake, stacked, quadzilla adrenaline. 1999 4wd auto, bone stock
 

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STOP! First is does not "shift" down from OD to 4th. 4th is OD. What is doing is you have the infamous "Lockup issue" Your torque convertor is probably fine. It is usually a symptom, not the problem. You are probably getting electrical interference coming out of the alternator causing the ECM/PCM to tell the torque converter to unlock. Sometimes you can clean all the battery cables and fix the problem, usually only temporary. The problem usually originates in the alternator. Take you alt off and have it tested an a rebuilder that can fully test it, not just an output test. It will probably test bad for other issues and needs replacement. Sometimes even the rebuilds are not good. The lockup problem can ruin the TC but not usually if y9ou fix the lock up. Replacing the TC will not fix the initial problem. A bad TC will usually show by slipping, not locking and unlocking back and forth. That is electrical. So clean terminals, reset APPS and check alternator for AC sine wave signals.
 

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Discussion Starter · #9 ·
STOP! First is does not "shift" down from OD to 4th. 4th is OD. What is doing is you have the infamous "Lockup issue" Your torque convertor is probably fine. It is usually a symptom, not the problem. You are probably getting electrical interference coming out of the alternator causing the ECM/PCM to tell the torque converter to unlock. Sometimes you can clean all the battery cables and fix the problem, usually only temporary. The problem usually originates in the alternator. Take you alt off and have it tested an a rebuilder that can fully test it, not just an output test. It will probably test bad for other issues and needs replacement. Sometimes even the rebuilds are not good. The lockup problem can ruin the TC but not usually if y9ou fix the lock up. Replacing the TC will not fix the initial problem. A bad TC will usually show by slipping, not locking and unlocking back and forth. That is electrical. So clean terminals, reset APPS and check alternator for AC sine wave signals.
It goes from 4th to 3rd around left turns and up hill. Would that still be a symptom of the alternator?
 

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I typically find that most shops suck at diagnostic work cause they don't listen to the customer completely and then an idea pops into their head. I have found that usually involves your wallet first and their time spent on the issue to a minimum. They are under pressure to earn a living so that becomes their priority sometimes. I have found better info on here than 6 out of 7 diesel shops around here. My pops use to say the simplest explanation is usually closest to the truth. If 14 other people here had the same problem I would investigate that rather than listen to a guy that spent 10 mins figuring it out. No use learning the same lesson if you don't have too.
 

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What speed are you going when it "shifts"? It will down shift automatically when you get down to about 42-45 mph. Above that I do not think it is shifting, I think it is dis-engaging lockup making the rpm jump about 400 rpm. Then it will go back and forth lock and unlock. There are lots of electrical triggers but most all are rooted in the bad alternator putting out bad AC sine waves. They interfere with the ecm signals to the torque convertor.
 

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Discussion Starter · #13 ·
She "chugs" when taking off almost like she's in second. If you have ever driven a standard and released the clutch too quickly that what she does. When we finally get to speed over 65 she's fine. Between 45 and 65, it will lock, unlock, drop to 3rd. RPM 2500, She slows to 35 by the time she gatherers herself to continue. When she unlocks, I release the gas and allow her to do her thing, Screw the people behind me on the road. I was told by the guy who check her out said my fluid was burnt. I have not driven her since Saturday.
 

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If the tc was shot then I would expect the RPMs to shoot up and feel limp almost. When dealing with tranny issues, you should take it to a trust worthy shop. most tranny shops don't care.
 

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I will repeat everything I told you above. Have your alternator tested by a very good rebuild shop, not a standard repair shop or parts store. Change the fluid. You may need a TC but you do not know that until you fix the electrical cause of the lockup and other problems. It is also probably causing it to start in second sometimes. Once you fix those, if it locks up and does not slip under load the TC is fine. The unlocking or starting in second has nothing to do with anything wrong with the TC, It is the electrical interference from the alt causing the ECM to tell the TC to unlock or shift. If the alternator is bad, which it very likely is it is a 150 to $250 fix for everything not nearly a $1000 for a new TC and more. Changing the TC first will fix none of your problems described.
 

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Discussion Starter · #16 ·
well I still don't know what is wrong with her, but I sold her to my brother who has means to fix her. When he gets her fixed I will report what was wrong for those who search this later. I will have a 2012 ram 2500 tomorrow. I will drive Nothin but Cummins.
 
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